Q: Is it possible to get a replacement USB drive.

I had occasion to need the very same thing (mind you, it's been over a year ago). I got nowhere with going through normal sales channels of Apple. I called tech support/AppleCare, and they were able to send me a replacement for a nominal charge. I don't know whether the situation was helped by the fact that i was still covered by AppleCare at the time. You may want to try going through parts ordering, versus online Apple Store.

Then there is also eBay. I see that a few sellers have them there.

Here is a link. I think this can be done by a tech savy user.

http://eshop.macsales.com/shop/SSD/OWC/Aura_Pro_Express

RFFS,

I think the OP is looking for a System/Recovery Disk (USB drive on 2010 model)

One of these....

You are right, somehow I posted to the wrong question!?!?